Course Of Mechanical Ventilation Research Articles

Oxidative stress in patients on mechanical ventilation

The appearance and intensity of oxidative stress were analyzed in the course of mechanical ventilation and parameters that could point toward potential lung damage. In three time intervals on day 1, 3 and 7 of mechanical ventilation, parameters such as: triglycerides, cholesterol, lactate, serum lactic dehydrogenase, acid-base balance and lipid peroxidation products--thiobarbituric acid reactive substances, were followed in 30 patients with head injuries. A decrease in the level of partial oxygen pressure (PaO2) (p < 0.01) and PaO2/FiO2 index (p < 0.05) in arterial blood was recorded on day 3 of mechanical ventilation. This was accompanied with an increase in alveolar-arterial difference (AaDO2) (p < 0.05), thiobarbituric acid reactive substances (p < 0.001) and lactic dehydrogenase (p < 0.001) comparing to day 1 of mechanical ventilation. The patients with initial PaO2 > 120 mmHg, had significant increase of thiobarbituric acid reactive substances and AaDO2 (p < 0.05) and fall of PaO2 (p < 0.001) on day 3 of mechanical ventilation. Oxidative stress and lipid peroxide production are increased during third day of mechanical ventilation leading to disruption of oxygen diffusion through alveolar-capillary membrane and reduction of parameters of oxygenation.

The endotracheal tube air leak test does not predict extubation outcome in critically ill pediatric patients

Endotracheal tube air leak pressures are used to predict postextubation upper airway compromise such as stridor, upper airway obstruction, or risk of reintubation. To determine whether the absence of an endotracheal tube air leak (air leak test >/=30 cm H2O) measured during the course of mechanical ventilation predicts extubation failure in infants and children. Prospective, blinded cohort. Multidisciplinary pediatric intensive care unit of a university hospital. Patients younger than or equal to 18 yrs and intubated >/=24 hrs. The pressure required to produce an audible endotracheal tube air leak was measured within 12 hrs of intubation and extubation. Unless prescribed by the medical care team, patients did not receive neuromuscular blocking agents during air leak test measurements. The need for reintubation (i.e., extubation failure) was recorded during the 24-hr postextubation period. Seventy-four patients were enrolled resulting in 59 observed extubation trials. The extubation failure rate was 15.3% (9 of 59). Seven patients were treated for postextubation stridor. Extubation failure was associated with a longer median length of ventilation, 177 vs. 78 hrs, p = 0.03. Extubation success was associated with the use of postextubation noninvasive ventilation (p = 0.04). The air leak was absent for the duration of mechanical ventilation (i.e., >/=30 cm H2O at intubation and extubation) in ten patients. Absence of the air leak did not predict extubation failure (negative predictive value 27%, 95% confidence interval 6-60). The air leak test was >/=30 cm H2O before extubation in 47% (28 of 59) of patients yet 23 patients extubated successfully (negative predictive value 18%). An endotracheal tube air leak pressure >/=30 cm H2O measured in the nonparalyzed patient before extubation or for the duration of mechanical ventilation was common and did not predict an increased risk for extubation failure. Pediatric patients who are clinically identified as candidates for an extubation trial but do not have an endotracheal tube air leak may successfully tolerate removal of the endotracheal tube.

Characteristics and factors associated with mortality in patients receiving mechanical ventilation: first Chilean multicenter study

The outcome of mechanically ventilated patients can be influenced by factors such as the indication of mechanical ventilation (MV) and ventilator parameters. To describe the characteristics of patients receiving MV in Chilean critical care units. Prospective cohort of consecutive adult patients admitted to 19 intensive care units (ICU) from 9 Chilean cities who received MV for more than 12 hours between September lst, 2003, and September 28th, 2003. Demographic data, severity of illness, reason for the initiation of MV, ventilation modes and settings as well as weaning strategies were registered at the initiation and then, daily throughout the course of MV for up to 28 days. ICU and hospital mortality were recorded. Of 588 patients admitted, 156 (26.5%) received MV (57% males). Mean age and Simplified Acute Physiology Score-II (SAPS II) were 54.6+/-18 years and 40.6+/-16.4 points respectively The most common indications for MV were acute respiratory failure (71.1%) and coma (22.4%). Assist-control mode (71.6%) and synchronized intermittent mandatory ventilation (SIMV) (14,2%) were the most frequently used. T-tube was the main weaning strategy. Mean duration of MV and length of stay in ICU were 7.8+/-8.7 and 11.1+/- 14 days respectively. Overall ICU mortality was 33.9% (53 patients). The main factors independently associated with increased mortality were (1) SAPS II > or =60 points (Odds Ratio (OR), 10.5; 95% CI, 1.04-106.85) and (2) plateau pressure > or =30 cm H2O at second day (OR, 3.9; 95% CI, 1.17-12.97). Conditions present at the onset of MV and ventilator management were similar to those reported in the literature. Magnitude of multiorgan dysfunction and high plateau pressures are the most important factors associated with mortality.

Características de los pacientes que reciben ventilación mecánica en unidades de cuidados intensivos: primer estudio multicéntrico chileno

The outcome of mechanically ventilated patients can be influenced by factors such as the indication of mechanical ventilation (MV) and ventilator parameters.To describe the characteristics of patients receiving MV in Chilean critical care units.Prospective cohort of consecutive adult patients admitted to 19 intensive care units (ICU) from 9 Chilean cities who received MV for more than 12 hours between September lst, 2003, and September 28th, 2003. Demographic data, severity of illness, reason for the initiation of MV, ventilation modes and settings as well as weaning strategies were registered at the initiation and then, daily throughout the course of MV for up to 28 days. ICU and hospital mortality were recorded.Of 588 patients admitted, 156 (26.5%) received MV (57% males). Mean age and Simplified Acute Physiology Score-II (SAPS II) were 54.6+/-18 years and 40.6+/-16.4 points respectively The most common indications for MV were acute respiratory failure (71.1%) and coma (22.4%). Assist-control mode (71.6%) and synchronized intermittent mandatory ventilation (SIMV) (14,2%) were the most frequently used. T-tube was the main weaning strategy. Mean duration of MV and length of stay in ICU were 7.8+/-8.7 and 11.1+/- 14 days respectively. Overall ICU mortality was 33.9% (53 patients). The main factors independently associated with increased mortality were (1) SAPS II > or =60 points (Odds Ratio (OR), 10.5; 95% CI, 1.04-106.85) and (2) plateau pressure > or =30 cm H2O at second day (OR, 3.9; 95% CI, 1.17-12.97).Conditions present at the onset of MV and ventilator management were similar to those reported in the literature. Magnitude of multiorgan dysfunction and high plateau pressures are the most important factors associated with mortality.

Changes in outcomes (1996???2004) for pediatric oncology and hematopoietic stem cell transplant patients requiring invasive mechanical ventilation*

To assess the following hypotheses regarding mechanically ventilated pediatric oncology patients, including those receiving hematopoietic stem cell transplant (HSCT) and those not receiving HSCT: 1) outcomes are more favorable for nontransplant oncology patients than for those requiring HSCT; 2) outcomes have improved for both populations over time; and 3) there are factors available during the time of mechanical ventilation that identify patients with a higher likelihood of dying. Retrospective review. Free-standing, tertiary care, pediatric hematology oncology hospital. All patients requiring invasive mechanical ventilation with a diagnosis of cancer or following HSCT from January 1996 to December 2004. Bivariate and multivariate analysis. Dates of admission were grouped into time periods for analysis: 1996-1998, 1999-2001, and 2002-2004. There were 401 courses of mechanical ventilation (329 patients) analyzed. Forty-five percent of HSCT admissions (92 of 206) vs. 75% of non-HSCT oncology admissions (146 of 195) were extubated and discharged from the pediatric intensive care unit (p < .0001). Twenty-five percent of HSCT vs. 60% of non-HSCT admissions survived 6 months (p < .0001). Among admissions with an abnormal chest radiograph and a PaO2/FiO2 ratio <200, pediatric intensive care unit survival increased for each successive time period, with 45% of HSCT and 83% of non-HSCT admissions surviving during 2002-2004. In multivariate analysis of all study patients, Pediatric Risk of Mortality scores on the day of intubation, allogeneic HSCT, cardiovascular failure, hepatic failure, neurologic failure, a previous course of mechanical ventilation within 6 months, and the time period intubated were associated with mortality. With the exception of time period, these same variables were associated with mortality in multivariate analysis of only HSCT patients. HSCT patients who require mechanical ventilation have worse outcomes than non-HSCT oncology patients. Outcomes for both groups have improved over time. Allogeneic transplant, higher Pediatric Risk of Mortality scores, need for repeated mechanical ventilation, and concomitant organ system dysfunction are risk factors for death.

Courses on mechanical ventilation in pediatrics: First experience in Spain

To analyse the initial experience in mechanical ventilation courses held by the Respiratory Group of the Spanish Paediatric Intensive Care Society. From 2002 to 2006, 15 courses on paediatric mechanical ventilation were held in eight hospitals in Spain, attended by a total of 367 physicians (53.4 % trainees and 46.6 % staff physicians from Paediatrics, Neonatology or Emergency). An initial theoretical written test of 40 questions was completed by participants, followed by short theory classes and practical workshops based on clinical situations, with ventilators and ventilation simulators, with five to seven students per workshop. At the end of the course participants completed a theoretical written test, in which it was considered necessary to answer correctly at least 70% of the questions, a practical evaluation (with assessment grades from 1 to 5) and a written survey about the quality of the course (with assessment grades from 0 to 10). In the initial test, only 20% of students answered 70% of questions correctly, whilst in the final test 93% hit this target, (p < 0.001). In the practical evaluation, 96% of students demonstrated sufficient acquisition of practical skills (grades equal to or greater than 3). In the participant survey, the course methodology was rated at 8.7 +/- 0.5, organisation 8.7 +/- 0.4, teaching staff 9.2 +/- 0.2, theoretical classes 8.7 +/- 0.4 and practical sessions 8.8 +/- 0.3. Mechanical ventilation courses are a useful educational method for health professionals in theoretical and practical mechanical ventilation.

Protective methods for patients' eyes during the course of mechanical ventilation

目的 探讨眼部程序化护理对机械通气患者暴露性角膜炎的预防效果.方法 收集217例昏迷或使用镇静剂,且机械通气≥24h的患者,分为观察组123例和对照组94例.观察组采取眼部清洁、涂红霉素眼膏/滴氯霉素眼药水、眼睑按摩、橡胶片盖眼的程序化护理;对照组仅采用涂红霉素眼膏/滴氯霉素眼药水和橡胶片盖眼的眼部护理.比较2组患者暴露性角膜炎的发生率.结果 观察组暴露性角膜炎发生率(9.8%)显著低于对照组(30.1%),x2=15.47,P＜0.01.结论 眼部程序化护理可有效预防机械通气患者眼部的并发症,提高患者的舒适度。

Factores asociados al pronóstico de los pacientes pediátricos ventilados mecánicamente. Un estudio internacional

Identify factors associated with the survival of pediatric patients who are submitted to mechanical ventilation (MV) for more than 12 hours. International prospective cohort study. It was performed between April 1 and May 31 1999. All patients were followed-up during 28 days or discharge to pediatric intensive care unit (PICU). 36 PICUs from 7 countries. A total of 659 ventilated patients were enrolled but 15 patients were excluded because their vital status was unknown on discharge. Overall in-UCIP mortality rate was 15,6%. Recursive partitioning and logistic regression were used and an outcome model was constructed. The variables significantly associated with mortality were: peak inspiratory pressure (PIP), acute renal failure (ARF), PRISM score and severe hypoxemia (PaO2/FiO2 < 100). The subgroup with best outcome (mortality 7%) included patients who were ventilated with a PIP < 35 cmH2O, without ARF, or PaO2/FiO2 > 100 and PRISM < 27. In patients with a mean PaO2/FiO2 < 100 during MV mortality increased to 26% (OR: 4.4; 95% CI 2.0 to 9.4). Patients with a PRISM score > 27 on admission to PICU had a mortality of 43% (OR: 9.6; 95% CI 4,2 to 25,8). Development of acute renal failure was associated with a mortality of 50% (OR: 12.7; 95% CI 6.3 to 25.7). Finally, the worst outcome (mortality 58%) was for patients with a mean PIP >/= 35 cmH2O (OR 17.3; 95% CI 8.5 to 36.3). In a large cohort of mechanically ventilated pediatric patients we found that severity of illness at admission, high mean PIP, development of acute renal failure and severe hypoxemia over the course of MV were the factors associated with lower survival rate.

An ultrasound imaging method for in vivo tracheal bulk and Young's moduli of elasticity

Alterations in neonatal airway mechanical properties resulting from ventilatory therapies such as mechanical ventilation have been implicated in airway collapse and chronic disease. Advances in ultrasound (US) technology allow for real-time imaging and accurate measurement of tracheal dimensions in vivo ; thus, changes in mechanical properties can be tracked longitudinally. In this report we introduce an adaptation of engineering concepts using US imaging data to study airway mechanics in vivo. In this protocol, tracheal segments are isolated in a spontaneously breathing newborn lamb model and the segments are exposed to time-cycled, pressure-limited mechanical ventilation. Serially, tracheal segments are filled with saline and pressure–volume relationships are recorded with stepwise volume infusions. US dimensional measurements of the segments are made while static (no distending pressure) and at pressure limits during dynamic ventilator cycling. US measurements are used to normalize pressure–volume data for resting volume, calculation of bulk modulus, stress–strain relationships and the adapted Young's modulus associated with tangential wall stress. Temporal changes in bulk and Young's moduli demonstrate the time dependence of alterations in conducting airway mechanical properties in vivo during the course of mechanical ventilation. This methodology will provide a means to evaluate respiratory therapies with respect to airway mechanics.

Successful use of recombinant activated FVII and aminocaproic acid in four neonates with life-threatening hemorrhage

Reports on the use of recombinant activated factor VII (rFVIIa) to counteract hemorrhagic shock in neonates and preterm infants are increasing. rFVIIa enhances thrombin generation in situations with impaired thrombin formation and, since thrombin has a crucial role in providing hemostasis, rFVIIa is regarded as a general hemostasis agent. Full thrombin generation is necessary for the formation of a stable fibrin plug resistant to premature fibrinolysis. Antifibrinolytic drugs are not recommended for the treatment of acute bleeding. We report four neonates (one with massive postsurgical hemorrhage after ileostomy and three with severe pulmonary hemorrhage in the course of mechanical ventilation for meconium aspiration syndrome, congenital heart disease and during postoperative resuscitation after cardiac surgery for congenital heart disease) who were successfully treated with multiple administration of rFVIIa (120 microg/kg per dose) and antifibrinolytic therapy - aminocaproic acid (100 mg/kg per dose). In a fibrinolytic environment therapeutic concentrations of rFVIIa may sometimes be insufficient to produce adequate amounts of thrombin necessary for stable clot structure. Laboratory data in three of our patients with pulmonary hemorrhage (low fibrinogen levels with slightly prolonged prothrombin time) supported this thesis, so we blocked fibrinolysis with aminocaproic acid and achieved a complete clinical and laboratory therapeutic effect.

Incidence, risk factors, and outcome of ventilator-associated pneumonia

Objective The purpose of this study is to determine the incidence, risk factors, and outcome of ventilator-associated pneumonia (VAP). Design Prospective cohort. Setting Three hundred sixty-one intensive care units (ICUs) from 20 countries. Patients and Participants Two thousand eight hundred ninety-seven patients mechanically ventilated for more than 12 hours. Measurements and Results Baseline demographic data, primary indication for mechanical ventilation, daily ventilator settings, multiple organ failure over the course of mechanical ventilation, and outcome were collected. Ventilator-associated pneumonia was present in 439 patients (15%). Patients with VAP were more likely to have chronic pulmonary obstructive disease, aspiration, sepsis, and acute respiratory distress syndrome. Mortality in patients with VAP was 38%. Factors associated with mortality were severity of illness, limited activity before the onset of mechanical ventilation and development of shock, acute renal failure, and worsening of hypoxemia during the period of mechanical ventilation. Case-control analysis showed no increased mortality in patients with VAP (38.1% vs 37.9%, P = .95) but prolonged duration of mechanical ventilation and ICU stay. Conclusion In a large cohort of mechanically ventilated patients, VAP is more likely in patients with underlying lung disease (acute or chronic). Ventilator-associated pneumonia was associated with a significant increase in ICU length of stay but no increase in mortality.

Intermittent spontaneous breathing protects the rat diaphragm from mechanical ventilation effects*

Short-term mechanical ventilation has been proven to reduce diaphragm force and fiber dimensions. We hypothesized that intermittent spontaneous breathing during the course of mechanical ventilation would minimize the effects of mechanical ventilation on diaphragm force and expression levels of transcription factors (MyoD and myogenin). Randomized, controlled experiment. Animal basic science laboratory. Male Wistar rats, weighing 350-500 g. Anesthetized and tracheotomized rats were submitted to either 24 hrs of spontaneous breathing (SB, n = 5), 24 hrs of continuous controlled mechanical ventilation (CMV, n = 7), or controlled mechanical ventilation with intermittent spontaneous breathing: 60 mins every 5 hrs of mechanical ventilation repeated four times (ISB60, n = 8) or 5 mins every 5 hrs 55 mins of mechanical ventilation repeated four times (SB5, n = 9). They were compared with control animals free from intervention (C, n = 5). The profile of the diaphragm force-frequency curve of the controls and SB group was significantly different from that of the ISB and CMV groups; especially, the mean asymptotic force was less in the ISB and CMV compared with controls and SB. CMV resulted in a significant decrease in the diaphragm type I (-26%, p < .05 vs. C) and type IIx/b (-39%, p < .005 vs. C and SB) cross-sectional area, whereas this was not observed in the ISB groups. Diaphragm MyoD protein expression was significantly decreased after ISB60 (-35%, p < .0001 vs. C and SB) and even more after CMV (-73%, p < .0001 vs. others). The same pattern was observed with myogenin protein levels. Positive relationships between diaphragm MyoD and myogenin protein levels and diaphragm force were observed. The data demonstrated that intermittent spontaneous breathing during the course of mechanical ventilation may minimize the deleterious effect of controlled mechanical ventilation on diaphragm force, fiber dimensions, and expression of transcription factors.

Nosocomial pneumonia: impact of a very early antimicrobial therapy

Nosocomial pneumonia (NP) severely complicates the course of mechanical ventilation. Although the need of an appropriate antimicrobial therapy adapted from the results of cultures from lower respiratory samples is well known, the best moment to start it is yet to be defined.

Predictive Factors and Long-Term Outcome of Respiratory Failure after Guillain-Barré Syndrome

To analyze predictive factors and long-term recovery in patients with Guillain-Barré syndrome (GBS) who are in need of mechanical ventilation. In this 15-year retrospective study, 77 adult patients were identified with GBS. A comparison was made between the clinical data from patients who required mechanical ventilation and those who did not. Furthermore, the therapeutic outcomes of those 25 patients in need of mechanical ventilation during hospitalization at 1 year were determined using a modified Barthel index. A score below 12 was defined as a poor outcome, whereas a score of 12 or more was good. The study revealed 32% of patients (25/77) in need of respiratory support during hospitalization. At a follow-up of 1 year among the 25 ventilated patients, 7 patients (28%) had normal or minor signs and symptoms, 6 had unassisted gait, 3 had assisted gait, 6 were wheelchair- or bed-bound, and 3 died. The cause of death was septicemia with septic shock in all 3 cases. Factors that predict respiratory failure in the study GBS patients were disability grade on admission and areflexia. Those ventilated patients who had low maximal inspiratory pressure (PImax) (<14.5 cmH2O) and maximal expiratory pressure (PEmax) (<13.5 cmH2O) values at the time of intubation and the presence of complications after mechanical ventilation inevitably had worse outcomes than those who had not. If low values of PImax and PEmax at intubation were detected, aggressive respiratory management, which might include tracheostomy to allow more efficient bronchial clearing, and prevention of complications caused by prolonged course of mechanical ventilation are essential to maximize the potential for survival.

Incidence, risk factors and outcome of barotrauma in mechanically ventilated patients.

To determine the incidence, risk factors, and outcome of barotrauma in a cohort of mechanically ventilated patients where limited tidal volumes and airway pressures were used. Prospective cohort of 361 intensive care units from 20 countries. A total of 5183 patients mechanically ventilated for more than 12 h. Baseline demographic data, primary indication for mechanical ventilation, daily ventilator settings, multiple-organ failure over the course of mechanical ventilation and outcome were collected. Barotrauma was present in 154 patients (2.9%). The incidence varied according to the reason for mechanical ventilation: 2.9% of patients with chronic obstructive pulmonary disease; 6.3% of patients with asthma; 10.0% of patients with chronic interstitial lung disease (ILD); 6.5% of patients with acute respiratory distress syndrome (ARDS); and 4.2% of patients with pneumonia. Patients with and without barotrauma did not differ in any ventilator parameter. Logistic regression analysis identified as factors independently associated with barotrauma: asthma [RR 2.58 (1.05-6.50)], ILD [RR 4.23 (95%CI 1.78-10.03)]; ARDS as primary reason for mechanical ventilation [RR 2.70 (95%CI 1.55-4.70)]; and ARDS as a complication during the course of mechanical ventilation [RR 2.53 (95%CI 1.40-4.57)]. Case-control analysis showed increased mortality in patients with barotrauma (51.4 vs 39.2%; p=0.04) and prolonged ICU stay. In a cohort of patients in whom airway pressures and tidal volume are limited, barotrauma is more likely in patients ventilated due to underlying lung disease (acute or chronic). Barotrauma was also associated with a significant increase in the ICU length of stay and mortality.

Effects of a multifaceted, multidisciplinary, hospital-wide quality improvement program on weaning from mechanical ventilation.

To examine the effects of a mechanical ventilation weaning management protocol that was implemented as a hospital-wide, quality improvement program on clinical and economic outcomes. Prospective, before-and-after intervention study. Data from a preimplementation year are compared with those of the first 2 yrs after protocol implementation. Patients older than 18 yrs in diagnosis-related group 475 and group 483, who were admitted to the adult medical, surgical, and cardiac intensive care units (ICU) in a university hospital. After the baseline year, a weaning management program was implemented throughout our institution. Primary endpoints were mortality, days on mechanical ventilation, ICU and hospital lengths of stay, hospital costs, and the percentage of patients requiring tracheostomy. The number of patients increased from 220 in the baseline year (year 0) to 247 in the first year (year 1), then to 267 in the second year (year 2). The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score increased from 22.2 to 24.4 in year 1 (p =.006) and to 26.2 in year 2 (p <.0005). When year 0 was compared with year 1, mean days on mechanical ventilation decreased from 23.9 to 21.9 days (p =.608), hospital length of stay decreased from 37.5 to 31.6 days (p =.058), ICU length of stay decreased from 30.5 to 25.9 days (p =.133), and total cost per case decreased from $92,933 to $78,624 (p =.061). When year 0 was compared with year 2, mean days on mechanical ventilation decreased from 23.9 days to 17.5 days (p =.004), mean hospital length of stay decreased from 37.5 to 24.7 days, mean ICU length of stay decreased from 30.5 to 20.3 days, total cost per case decreased from $92,933 to $63,687, and percentage of patients requiring tracheotomy decreased from 61% to 41% (all p <.0005). There was also a reduction in the percentage of patients requiring more than one course of mechanical ventilation during the hospitalization from 33% to 26% (p =.039), a total cost savings of $3,440,787 and a decrease in mortality between all 3 yrs from 32% to 28% (p =.062). A multifaceted, multidisciplinary weaning management program can change the process of care used for weaning patients from mechanical ventilation throughout an acute care hospital and across multiple services. This change can lead to large reductions in the duration of mechanical ventilation, length of stay, and hospital costs, even at a time when patients are sicker.

Characteristics and outcomes in adult patients receiving mechanical ventilation: a 28-day international study.

The outcome of patients receiving mechanical ventilation for particular indications has been studied, but the outcome in a large number of unselected, heterogeneous patients has not been reported. To determine the survival of patients receiving mechanical ventilation and the relative importance of factors influencing survival. Prospective cohort of consecutive adult patients admitted to 361 intensive care units who received mechanical ventilation for more than 12 hours between March 1, 1998, and March 31, 1998. Data were collected on each patient at initiation of mechanical ventilation and daily throughout the course of mechanical ventilation for up to 28 days. All-cause mortality during intensive care unit stay. Of the 15 757 patients admitted, a total of 5183 (33%) received mechanical ventilation for a mean (SD) duration of 5.9 (7.2) days. The mean (SD) length of stay in the intensive care unit was 11.2 (13.7) days. Overall mortality rate in the intensive care unit was 30.7% (1590 patients) for the entire population, 52% (120) in patients who received ventilation because of acute respiratory distress syndrome, and 22% (115) in patients who received ventilation for an exacerbation of chronic obstructive pulmonary disease. Survival of unselected patients receiving mechanical ventilation for more than 12 hours was 69%. The main conditions independently associated with increased mortality were (1) factors present at the start of mechanical ventilation (odds ratio [OR], 2.98; 95% confidence interval [CI], 2.44-3.63; P<.001 for coma), (2) factors related to patient management (OR, 3.67; 95% CI, 2.02-6.66; P<.001 for plateau airway pressure >35 cm H(2)O), and (3) developments occurring over the course of mechanical ventilation (OR, 8.71; 95% CI, 5.44-13.94; P<.001 for ratio of PaO(2) to fraction of inspired oxygen <100). Survival among mechanically ventilated patients depends not only on the factors present at the start of mechanical ventilation, but also on the development of complications and patient management in the intensive care unit.

Nosocomial pneumonia during acute respiratory distress syndrome

The Acute Respiratory Distress Syndrome (ARDS) shares with nosocomial pneumonia aetiological, physiopathological and diagnostic properties. This report will focus on the importance of nosocomial pneumonia as a complication of ARDS and review data on prevalence, incidence and the impact of nosocomial pneumonia on outcome in patients with ARDS. Prevention strategies are imperative to protect ARDS patients for nosocomial pneumonia. The prevalence of nosocomial pneumonia seems to be at least 8%. The incidence varies largely with the study design but an estimate that every second patient with ARDS will suffer at least one episode of pneumonia during the course of mechanical ventilation, seems to reflect clinical experience and data. However, given the high incidence of nosocomial pneumonia during the course of ARDS and the impact of adequate antibiotic therapy on survival, microbiological surveillance seems to be appropriate even in the clinical routine.

Nosocomial pneumonia during acute respiratory distress syndrome

The Acute Respiratory Distress Syndrome (ARDS) shares with nosocomial pneumonia aetiological, physiopathological and diagnostic properties. This report will focus on the importance of nosocomial pneumonia as a complication of ARDS and review data on prevalence, incidence and the impact of nosocomial pneumonia on outcome in patients with ARDS. Prevention strategies are imperative to protect ARDS patients for nosocomial pneumonia. The prevalence of nosocomial pneumonia seems to be at least 8%. The incidence varies largely with the study design but an estimate that every second patient with ARDS will suffer at least one episode of pneumonia during the course of mechanical ventilation, seems to reflect clinical experience and data. However, given the high incidence of nosocomial pneumonia during the course of ARDS and the impact of adequate antibiotic therapy on survival, microbiological surveillance seems to be appropriate even in the clinical routine.

Continuous infusion of ketamine in mechanically ventilated children with refractory bronchospasm.

To determine whether ketamine infusion to mechanically ventilated children with refractory bronchospasm is beneficial. Retrospective chart review. Pediatric intensive care unit (PICU) of a children's hospital. Seventeen patients, ages ranging from 5 months to 17 years (mean 6 +/- 5.7 years), were admitted to our PICU over a 3-year period and received ketamine infusion during a course of mechanical ventilation. The patients had acute respiratory failure associated with severe bronchospasm due to status asthmaticus (n = 11), bronchiolitis caused by respiratory syncytial virus (n = 4), and bacterial pneumonia (n = 2). All patients had been mechanically ventilated for 1-5 days (2.2 +/- 1.5 days) and received conventional treatment to relieve bronchospasm for more than 24 h prior to the initiation of ketamine treatment. An intravenous bolus of ketamine of 2 mg/kg, followed by continuous infusions of 20-60 micrograms/kg per minute (32 +/- 10 micrograms/kg per minute) was administered to all patients without changing their preexisting bronchodilatory regimen. Benzodiazepines were also given intravenously to all patients during the ketamine treatment. The PaO2/FIO2 ratio in all patients (n = 17) and the dynamic compliance in the volume-preset mechanically ventilated patients (n = 12) were calculated. The PaO2/FIO2 ratio increased significantly from 116 +/- 55 before ketamine, to 174 +/- 82, 269 +/- 151, and 248 +/- 124 at 1, 8, and 24 h respectively, after the initiation of the ketamine infusion (p < 0.0001). Dynamic compliance increased from 5.78 +/- 2.8 cm3/cmH2O to 7.05 +/- 3.39, 7.29 +/- 3.37, and 8.58 +/- 3.69, respectively (p < 0.0001). PaCO2 and peak inspiratory pressure followed a similar trend of improvement with ketamine administration. The mean duration of the ketamine infusion was 40 +/- 31 h. One patient required glycopyrrolate 0.4 mg/day to control excessive airway secretions and one patient required an additional dose of diazepam to control hallucinations while emerging from ketamine. All patients were successfully weaned from mechanical ventilation and discharged from the PICU. Continuous infusion of ketamine to mechanically ventilated patients with refractory bronchospasm significantly improves gas exchange and dynamic compliance of the chest.